Filter Array Not in Another Array

You can simply run through obj1 using filter and use indexOf on obj2 to see if it exists. indexOf returns -1 if the value isn't in the array, and filter includes the item when the callback returns true.

var arr = obj1.filter(function(item){
  return obj2.indexOf(item.id) === -1;
});

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With newer ES syntax and APIs, it becomes simpler:

const arr = obj1.filter(i => !obj2.includes(i.id))